1. Field of the Invention
The present invention relates to a device for varying valve timing of an internal combustion engine. More specifically, the present invention relates to a device capable of varying valve timing by properly changing phase of a cam shaft and pausing the cam shaft according to traveling conditions, in particular for V-type engines.
2. Description of Related Art
An internal combustion engine, such as a vehicle engine, should regulate valve timing properly to produce maximum engine power. Many different types of devices are capable of regulating valve timing. Some of these devices change cam phase of a cam shaft to regulate valve timing. In one type of device, a helical gear places a cam shaft pulley in engagement with the cam shaft. In another type of device, structure is provided for moving a cam shaft sprocket to place the sprocket in engagement with the cam shaft. However, some of these devices have limited durability and/ or high manufacturing costs.
In light of the foregoing, there is a need in the art for an improved device for varying valve timing.